Mark Svenvold

On the morning of May 20th, hundreds of people—scientists, film crews, and a trove of amateur storm chasers—seemed to settle, all at once, on an area somewhere west of I-35, near Purcell, Oklahoma, and on one farther north, near Paul’s Valley, about eighty miles south of Oklahoma City, as the most likely places in the country to spawn tornadoes that day. Josh Wurman, of the Center for Severe Weather Research—the handsome, silver-haired scientist on the Discovery Channel reality show “Storm Chasers”—had parked his Doppler-equipped trucks in Paul’s Valley, splitting the difference between the sites, one north and one south. The southern targets seemed like the best bet; the northern storms looked weak and disorganized.

It is a testament to how far the science of tornado forecasting has progressed that everybody knew something big was going to happen, and that it was going to happen on that day. The secret of tornadogenesis remains a mystery; in truth, because of the laws of chaos theory, tornadoes may represent the absolute outer limit of what humans can know and predict about nature. At 11 A.M., the Norman, Oklahoma, branch of the National Weather Service had issued a statement saying, in effect, that, if a thunderstorm formed, there was a high probability that it would produce a violent tornado.

Sunlight falls like cash through the canopy.One wants to say “filters down,” but really it’s a cascadeof plenty, a rich comedy in which each leaf’s increaseis summoned and rewarded. Q: Can a leaf be as bigas a bus? A: Yes, it can, in the Yucatan.The grackle struts through its portico. Above and all aroundthe whistle and hoot, the high glissando, the bell and echo,the flatted fifth, the celestial chitter, the honk, the joke noteon a whoopee cushion, the clarion rising above the clatter,the squelch and squirch and screech of a manic communiquékeeps slipping, like background noise, into the broad clothof a morning above us and in us, like some momentary shaft,of sunlight on the floating seed of the ceiba tree,that hangs like this and like that in the shadows and subaltern greens.Meanwhile, the doves, who hoard all vowels,pass it one to another among the trees: the sky, the sun,and the great limestone rivers of the dead, are one.